Current female sterilization procedures often make use of implants that are placed within the fallopian tubes. For example, the Adiana® Permanent Contraception (Hologic, Inc., Marlborough, Mass.) is a minimally invasive procedure in which a delivery catheter is passed through the vagina and cervix and into the uterus. A low level of radiofrequency energy is delivered to a small section of each fallopian tube to create a superficial lesion. A small implant is then placed within each fallopian tube at the location where the lesions were created. Over a period of time, tissue grows into and/or around the implants leading to complete occlusion of the fallopian tubes to thereby provide the desired sterilization. Such implants and procedures are described, for example, in U.S. Pat. No. 7,220,259, which is incorporated herein by reference.
It is often desired, and clinically required per the FDA approved instructions for use (IFU) of the product, to use a post-procedure verification method to ensure that the fallopian tube(s) have indeed been fully occluded to yield the desired sterilization. Typically, occlusion is verified after the sterilization procedure with the aid of hysterosalpingogram (HSG). An HSG is a radiographic technique in which a contrast media (e.g., oil or water soluble fluid containing a radiographically opaque compound of a material such as iodine) is injected into the uterine cavity and fallopian tubes via a transcervicallly-placed cannula. Radiographic images are taken to delineate the inside of the uterus and fallopian tubes. Tubal occlusion is verified by the lack of contrast media past a specific location in the tube (or by lack of contrast media in certain anatomical spaces such as the pouch of Douglas). There are several possible limitations to using HSG to verify occlusion. First, the patient and physician are exposed to radiation. Second, the determination of occlusion/patency is done visually and can thus be prone to human error. Tissue and bone of different densities can obstruct the view of pooling contrast media and premature reading of x-rays may not identify slow pooling contrast media. Lastly, a radiologist is needed in addition to a gynecologist, thus complicating this medical procedure and increasing the likelihood for patient non-compliance.
There have been some successful efforts to develop new devices and procedures to verify tubal occlusion following the aforementioned sterilization procedure and similar procedures. For example, US patent publication no. 2008/0167664, which is incorporated herein by reference, describes a device for verifying occlusion of the fallopian tube including an elongate gas delivery having a lumen disposed therein adapted for sealing engagement with the uterus. The device includes a pressurized insufflation gas source coupled to the elongate gas delivery member. The device includes a pressure sensor or gauge to measure intra-uterine pressure to verify occlusion of the fallopian tubes. A possible limitation of this device is that it does not include the ability to confirm a proper seal between the patient's anatomy and the device.
It is an object of the present invention to provide devices and methods to verify or detect occlusion of a body lumen, such as a fallopian tube, that avoid the limitations of the prior art.